Fire bosses fear repeat of epic Nelson blaze

South Island fire officials are warning locals a single spark could see thousands of acres alight. 

In early February last year, fires in Nelson burned through 2500 hectares. Within days it was the biggest the country had seen since the 1950s, and thousands of residents were forced out of their homes. It took a month to get the blazes under control.

Two people were later charged with arson, both pleading not guilty.

Otago deputy principal rural fire officer Bobby Lamont says warnings this summer are at their most extreme, even that far south.

"We're in a total fire ban through central Otago, and we are seeing some extreme fire dangers through the afternoons," he told Newshub.

Nelson City Council group manager Alec Louverdis said people can't be too careful.

"That risk is certainly heightened - that's not only on the back of not only the fires that happened last year, but certainly that's first and foremost in our minds. We certainly do not want to experience that again... they take no prisoners."

Nelson also has a fire ban in place, with mowing lawns being restricted to early mornings when there's dew still on the ground. 

Lamont, says if people aren't careful, it could spell disaster. 

"If we did have an ignition in these conditions, the fire's going to be extremely hard to control and it will move rapidly... Any kind of spark will just start a fire, and it will carry quickly." 

Louverdis said after last year and the recent Australian bushfires, people understand now how bad fires can be.

"The fires that we had last year were pretty devastating, but it could it have been worse than that? Potentially it could. We've got large tracts of trees, and forests and pine. Anything is possible - we've seen what can happen in Australia."

"Matches are a no-no," added Louverdis. "That's definitely something we would want to see anywhere in our forests and parks. We recommend people remain in the lower areas of those reserves."

He said if people travel too deep into the reserves, they may find it hard to self evacuate in the event of a fire.

 Fire and Emergency officials earlier this week called for 30m-plus tree-free zones around homes to save them in the event of a blaze.